• Title/Summary/Keyword: Assessment of deterioration

Search Result 330, Processing Time 0.029 seconds

A Study of the Trend on Quality of Life with Stroke (노졸중환자의 삶의 질에 대한 연구 동향)

  • Lee, Cu-Rie;Kim, Keun-Jo
    • Journal of Korean Physical Therapy Science
    • /
    • v.6 no.3
    • /
    • pp.41-52
    • /
    • 1999
  • Stroke is the leading cause of adult disability and the third leading cause of adult death in the world. Stroke has an impact on the physical, psychological and social dimensions of quality of life. An increasing number of authors have reported a deterioration of the quality of life in a large proportion of patients after a stroke. Just as satisfaction with each dimension varies to everyone, the importance of each dimension also varies and does not impact equally on the quality of life. So assessment on the quality of life has to adopt a multidimentional approach and to make use of the subjective and objective indicators.

  • PDF

Study on the Amount of Critical Corrosion Products of Reinforcement inducing Concrete Cover Cracking with Finite Element Analysis (유한 요소법을 이용한 콘크리트 벽체 균열을 발생시키는 철근의 임계 부식량에 대한 연구)

  • 김광웅;장상엽;조용범;김용철;고영태
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 2002.05a
    • /
    • pp.361-366
    • /
    • 2002
  • The deterioration of concrete structure due to corrosion of the reinforcement has created big financial losses on the overall industries. The volume expansion of the corrosion products causes internal pressure to concrete wall around reinforcing bar. If the maximum principal stress induced by internal pressure exceeds the tensile strength of the concrete at any point of time, a crack forms at any point of material. Therefore, in terms of life assessment of concrete structure, it is very important to predict the amount of corrosion products which induces initial concrete cracking. With this objective, this paper proposes the critical amount of corrosion products at interface between reinforcement and concrete using finite element analysis. If an actual survey of corrosion rates could be made, the model might supply information for condition assessment of existing concrete structure. As the mechanical properties of corrosion product and instantaneous geometry of corroded steel are considered in the analysis, the value obtained will be more realistic.

  • PDF

Consideration on the Risk of Corrosion Assessment in Reinforced Concrete Structure by Corrosion Potential Criterion (부식전위 기준에 의한 철근콘크리트 구조물의 부식진단의 위험성에 관한 고찰)

  • Jeong, Jin-A
    • Corrosion Science and Technology
    • /
    • v.14 no.3
    • /
    • pp.147-152
    • /
    • 2015
  • Corrosion of steel reinforcement is a major factor in the deterioration of harbour and bridge structure. Steel corrosion in concrete must be checked for assessing the condition of a reinforced concrete structure. There are several ways how to measure the corrosion condition of reinforced concrete, but the corrosion potential measurement is a very simple, rapid, cost-effective and non-destructive technique to evaluate the severity of corrosion in reinforced concrete structure, therefore commonly used by engineers. However some particular situations may not relate to the reinforcement corrosion probability and a simple comparison of the corrosion potential data with the ASTM C876 Standard on steel reinforcement corrosion probability could be meaningless and not give reliable informations because of environment factors as oxygen concentration, chloride content, concrete resistance. Therefore this paper explains the risk of corrosion assessment in reinforced concrete structure and how many factors can affect the reliability of the corrosion potential data.

Safety diagnosis process for deteriorated buildings using a 3D scan-based reverse engineering model

  • Jae-Min Lee;Seungho Kim;Sangyong Kim
    • Smart Structures and Systems
    • /
    • v.31 no.1
    • /
    • pp.79-88
    • /
    • 2023
  • As the number of deteriorated buildings increases, the importance of safety diagnosis, maintenance, and the repair of buildings also increases. Traditionally, building condition assessments are performed by one person or one company and various inspections are needed. This entails a subjective judgment by the inspector, resulting in different assessment results, poor objectivity and a lack of reliability. Therefore, this study proposed a method to bring about accurate grading results of building conditions. The limitations of visual inspection and condition assessment processes previously conducted were identified by reviewing existing studies. Building defect data was collected using the reverse-engineered three-dimensional (3D) model. The accuracy of the results was verified by comparing them with the actual evaluation results. The results show a 50% time-saving to the same area with an accuracy of approximately 90%. Consequently, defect data with high objectivity and reliability were acquired by measuring the length, area, and width. In addition, the proposed method can improve the efficiency of the building diagnosis process.

A Decision Support Methodology for Remediation Planning of Concrete Bridges

  • Rashidi, Maria;Lemass, Brett
    • Journal of Construction Engineering and Project Management
    • /
    • v.1 no.2
    • /
    • pp.1-10
    • /
    • 2011
  • Bridges are critical and valuable components in any road and rail transportation network. Therefore bridge remediation has always been a top priority for asset managers and engineers, but identifying the nature of true defect deterioration and associated remediation treatments remains a complex task. Nowadays Decision Support Systems (DSS) are widely used to assist decision makers across an extensive spectrum of unstructured decision environments. The main objective of this research is to develop a requirements-driven methodology for bridge monitoring and maintenance which has the ability to assess the bridge condition and find the best remediation treatments using Simple Multi Attribute Rating Technique (SMART); with the aim of maintaining a bridge within acceptable limits of safety, serviceability and sustainability.

Failure Risk Assessment of Reinforced Concrete Sewer Pipes on Joint-Related Defects (원심력철근콘크리트관의 결함에 따른 심각도 평가 -이음부 사례를 중심으로-)

  • Han, Sangjong;Shin, Hyunjun;Hwang, Hwankook
    • Journal of Korean Society of Water and Wastewater
    • /
    • v.27 no.6
    • /
    • pp.787-796
    • /
    • 2013
  • Sewer joint-related defect is one of the most common domestic sewer defects along with the lateral pipe problem. However, there are currently no criteria that precisely assess the joint-related sewer defects. Therefore, this study examined the joint-related sewer defects found in domestic circumstances, classified them according to the suggested defect code, and presented the examples of defect pictures. Each defect code was organized as the process of out of pipeline alignment (OPA) which shows the progress in deterioration. Each defect was classified into 5 grades depending on appropriate repair and rehabilitation method. The result of this study is expected to be useful for domestic CCTV inspectors to assess the sewer condition and helpful for managers to make a decision of repair and rehabilitation.

Electrical Characteristics Test of Distribution Polymer Lightening Arresters (배전용 폴리머 피뢰기의 전기적 특성시험)

  • Kwon, Tae-Ho;Lee, Byung-Sung;Song, Il-Keun;Kim, Dong-Myung;Yoon, Tae-Sang;Jung, Sang-Bong
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
    • /
    • 2004.05a
    • /
    • pp.546-549
    • /
    • 2004
  • This paper describes the electrical characteristics of the polymer lightning arresters(L.As) used to protect distribution lines and power facilities from surge. For the relative comparison, the characteristics assessment was done for 2 states of L.As before and after water immersion treatment. The L.As for the comparative test were immersed with water of $95[^{\circ}C]$ considered a severe condition. After the immersion treatment, the assessment was carried out for material analyses in chemical structure(FTIR : fourier transform infrared spectrophotometer). Electrical performance measured insulation resistance measurement, leakage current measurement, critical operation voltage measurement etc.. In addition to, the results were compared with those for the L.As deteriorated in the field. Thus, the accelerative deterioration degree of polymer materials by immersion treatment was evaluated, by which the structural defects of the polymer L.As could be inferred.

  • PDF

HOLISTIC DECISION SUPPORT FOR BRIDGE REMEDIATION

  • Maria Rashidi;Brett Lemass
    • International conference on construction engineering and project management
    • /
    • 2011.02a
    • /
    • pp.52-57
    • /
    • 2011
  • Bridges are essential and valuable elements in road and rail transportation networks. Bridge remediation is a top priority for asset managers, but identifying the nature of true defect deterioration and associated remediation treatments remains a complex task. Nowadays Decision Support Systems (DSS) are used extensively to assist in decision-making across a wide spectrum of unstructured decision environments. In this paper a requirements-driven framework is used to develop a risk based decision support model which has the ability to quantify the bridge condition and find the best remediation treatments using Multi Attribute Utility Theory (MAUT), with the aim of maintaining a bridge within acceptable limits of safety, serviceability and sustainability.

  • PDF

Safety factor calibration for bridge concrete girders

  • Silva, Rita C.;Cremona, Christian
    • Structural Engineering and Mechanics
    • /
    • v.49 no.2
    • /
    • pp.163-182
    • /
    • 2014
  • Safety factors proposed in codes CEB, B.A.E.L 91 and EUROCODE 1 cover a great number of uncertainties; making them inadequate for the assessment of existing structures. Suitable safety factors are established using a probabilistic assessment, once real dimensions, materials strength and existing structures deterioration mechanisms are taken into account. This paper presents a calibration method for safety factors using a typical set of RC bridges in France. It considers the principal stages of corrosion provoked by $CO_2$ and $Cl^-$ penetration and threshold indexes (${\beta}_0$) for existing structures. Reliability indexes are determined by the FORM method in the calibration method.

PERFORMANCE INDEX-An Assessment Indicator of Concrete Bridges (콘크리트 교량의 상태 평가를 위한 성능지수)

  • Kim, Kyoung-Soo;Cabrera, J.G.
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.1 no.2
    • /
    • pp.131-140
    • /
    • 1997
  • 콘크리트 교량을 저렴하고 신속하게 상태 평가를 하기 위하여 성능 지수(Performance Index)를 제안한다. 이 기법은 육안 검사에 의하여 발견된 결함의 범위와 심각도를 사용하여 콘크리트 교량의 전반적인 상태를 신속하게 등급화 하고 콘크리트 교량의 노출 조건을 고려하여 콘크리트 성능을 정량적으로 평가한다. 또한 본 연구에서는 상기한 성능 지수 기법의 타당성을 증명할 수 있는 정밀 안전 진단 시험결과를 활용하여 6개의 주요 노후화 원인을 고려하는 또 다른 성능 지수를 제안한다. 이러한 두 상태 평가 방법이 영국의 실제 교량 상태 평가 자료를 바탕으로 한 상태 평가 결과를 퍼지 집합 이론(fuzzy set theory)으로 분석한 결과와 비교하여 방법의 정당성 및 신뢰성을 논의한다.

  • PDF